It is often necessary to install a shaft through a housing bore having a shaft seal already mounted therein, the seal having one or more sealing lips designed to sealingly contact the shaft after installation thereof through the housing bore and seal. During shaft installation, the seal lip or lips can be damaged such as by being cut or distorted. Further, if the seal includes a lip extending in the direction opposing the direction of shaft installation, such opposing lip can be inverted. In addition, a garter spring, if present, can be damaged or dislocated from the spring groove. Contributing factors to such seal and/or spring damage are: (1) insufficient chamfer or radius on the lead-in edge of the shaft; (2) misallignment of the shaft; (3) high degree of interference between the seal lip and the shaft; (4) opposing cold-formed polytetrafluoroethylene lip or polytetrafluoroethylene-lined lip; (5) the lip element being weakly supported; (6) the shaft having a spline, keyway, tapped hole, etc.
One solution to this problem in the prior art is the use of a metal or plastic cylindrical sleeve that has an I.D. larger than the O.D. of the shaft. This sleeve is inserted into the seal and then the shaft is installed and the sleeve protects the seal lips. The sleeve is then pulled axially out of the seal and removed off of the outer end of the shaft. However, such a sleeve can not be used in all situations, such as when there is another machine element (either on the shaft or positioned very close to the housing) located such as to prevent the sleeve from sliding off of the outer end of the shaft.
It is an object of the present invention to provide a tool and method for preventing damage to the lip or lips of a seal mounted in a bore of a housing during installation of a shaft through the housing bore.
It is another object of this invention to provide such a tool and method that can be used in all situations including those in which the above-described prior art system can not be used.
It is a further object of this invention to provide such a tool and method wherein the tool's protective sleeve can be moved axially out of the seal and then radially off of and away from the shaft.
It is another object of the invention to provide such a tool and method wherein the protective sleeve can be easily inserted into the seal without expanding the seal lips and wherein such expansion is done by the shaft during shaft installation.